John gaiidner



@atten gisten gamut @fgt IMPROVEMENT IN GAIPING SGREWS.

@its ,stimule referat tu in tigtse e'ttersttent mit making putt nt tigt tame.

TO WHOM IT MAY CONCERN: Y

Be it known that I, JOHN GAi'tDNEn,-of New Haven, in the county of New Haven, and State of Connecticut,

have invented certain new and useful Improvem'cntsin Gapped Screws; and I hereby declare the following to be a full, clear, and exact description of the same, reference being ltad to the accompanying drawings, in which-P Figure l represents a top view of acap made in. accordance'with my invention. vFigure 2'is a vertical section on the line a: y, iig. 1.

Figure 3 is a. like section of a modified form. of the cap in the direction of the length of the nick. Figure 4 is a vertical section of so much of an apparatus for closing thecap uponthe head of the screw as is needed to illustrate my invention.

Figure 5 is a vertical'section of a round-headed, and Figure 64a like section of a {iat-headed capped screw, the section in'each case being transverse to the nick vin the screw-head and cap.

MyV invention relates'to the method of `capping screws, by closing upon the head of'the screw a metal cap' in which a. slot has been` formed to correspond withthe nickin the screw-head.

.One important drawback to 'the successful operation of this and other methods of capping screws has arisen from the diculty which has been experienced in` adjusting the scrcwland its cap in the closing-die to their `proper relations to each other, so that the slotin the cap shall' be brought immediately over the nick in the screw, and in order to eect this result mechanisms of more or less complicated structure'have been required." And in like mannerwhen a blank cap is closed upon the screw-head, as in some eases has been done in order to find the nick in the screw-head so as to punch thc slot in the cap, it becomes necessary to employ apparatus of a peculiar nature to tind the nick, and to form the slot Vwith accuracy and without damage to the cap.

The object of my invention is to remedy these diiculties, and to so form the cap that it may be 'closed upon the Vscrew-head in any ordinary or suitable die without the addition ofthe mechanisms above mentioned, as heretofore 'required to hold the cap and screw in their proper relations to each other. To this end, in forming the slot in the cap, I cut ont the metal ou the sides of the slot only, without disconnecting itl at the e ,.ds of the slot from the other portion of the cap, and the metal strip thus formed is depressed'or forced below the face of the cap, so that when the latteris applied to the screw-head, the metal-strip will liue', or bein contact with the bottom of the nick in the said screw-head.V In order to thus form theslot inl the cap, it 'can be placed upona die of suitable form, and then, by the action of a punch or dio, the sides of the slot cut out and the metal strip depressed, as above stated. VWhen the nick in the screw-head is of no great depth, as in the case of fiat-headed screws, the sides of the slot in the cap need not'be out out, but by the action of a die or punch, as. before, the cap may be depressed at the point where the slot is to' be formed without cutting, so that when it is applied to the screw-head, the sides, as well as the bottoni of the nick in the latter, will be 'lined by thc cap, which will thus cover and extend continuously over every portion of the screw-head. p

Among the many advantages which result from iny improved method of forming the slot or depression in the cap, there are two of special importance:

First, the metal strip, or depression formed in the cap, serves to centre or to assure Vthe screw and cap in their proper relations to each other during the operation oi' capping the. screw., When the cap and screw" are placed together in the closing-die, the portion of the cap which is depressed tits in the nick in the screw-head,

and thus holds the screw'and cap in'position until thelatter, by the action of thedie, is closed tirmlyupon the screw-head.

Second, in using ordinary capped screws, in which the metal is entirely cut away at the point where the slot,

is formed, itot'tcn happens that the screw-driver slips from the nick, :'ind, catchingfagainst the metal cap, causes it to turn so as to throw the slot out oi' line with the niek. But under my inventionfthe depressed metal of the cap which lines the bottom or botton and sides of the nick in the screw-head, being connected with and forming part of the cap, prevents the latter from turning, and holds the slot in the same to its place over the nick in the screw.

There are also other advantages incident lo this method of lining the nick in the screw-head, as, forfinstance,

mina .2

a. more ornamental appearance is given the screw, und the nick in the suine proltcted from rust and consequent damage. l i

In order that the nature` of my invention may be the better understood, I will now proceed to a more detailed description. of the manner in which theaimeis or moy beca-ried into effect, by'refererfce to the drawings accompanying and forming port of this specification. i v

-The cap A, which is made'of brass or other suitable metal, after being struck up in the usual manner into lthe required form, isplnced upon a die, where, by the action of apuneh ot' suitable form, the slot a is formed.

The metal is cut away on the sides of the slot only, and not. at the ends c, where it stillr remnins connected with the cap. I he metal strip d, thus formed, is`by thejaction of the punch` depressed below -the surface of the cap to a distance corresponding tothe depth of the'niek in the screw-headto which the cap is to be npplied, as seen, in g. 3. v Y

' Instead of rst striking up they cup into shape, and then forming the slot, the-two operations may, ii'iiesired, be performed simultaneously in die of suitable construction. In case .the cap is formed ,asrshown-iw vfigs. 1 and 2, to'it a. round-headed screw, it is preferable, owing to the depth ofthe nick in such screws, to out away the metal on the sides of the slot, as represented. But when the cop is shaped to lit a flot-headed screw, ns seen in g. 3, the metal at the point where the slot is usually formed, instead otbeing cut away, asfshownin the drawings, may be simply struck up or depressed so as to fit the nickv in the scr`eWhend,the cap'in vsuch onse being composed of a. continuous and unbroken piece' of metal. The lcup" in which the slot ist-hns formed, is, together with the screw to be capped, plneed in any ordinary or suitablefscreueapping apparatus, and bythe action of this the cap is then closedl tightly upon the screw-head. The strip or depressed portion i of the cap fits in the nick in the screw-head. und serves to hold the slottedoap in proper position upon the said head during the process of the operation.

In iig. 4 is represented, in illustration of my invention, one method of closing the cap. The closing-die is composed of the two pnrtsB C, the former, which is stntionory :rnd-attached to the bed of 'the machine, being intended to receive the cap and heed of the screw,the letter constituting the movable portion of the apparatus, which,'whenpressed uponthe bed B,.will close the cap upon` the screw. The cup A is first placed in aninverted positionin the matrix or form h of the bed v2B, and thehbad of .the screw is then placed in the cap, being turned until the metal strip d of the cap ts in the nick, as seen in tbc--iigure referred to. When the two are thus fitted together, it will be seen that no matter to what extent 4the screw may' be turnedin' the die, the strip d, which is h'eld in the nick of the screw, will cause the cap to follow such rnovcment,-.tbus maintaining nt all times the slot in the cap in its proper relations to the nick inthe screw-head. The die C, in its descent, closes that portion of the cap which extends above the screw-head, upon thehend, `and thus'unites the tivo firmly together, as seen in figs. 5 and 6, the former representing a round-headed screw capped and finished, and the latter being a like representation of a {lat-headed screw.

Having now described m-y invent-ion, and the manner in which the saine is or may be carried into eiTect,

what I claim, and desire to .secure by Letters Patent, is-j- 1. In the method of capping screws, I claim cutting away or depressing the cap atHthe-point where it meets thel nick in the screw-head, substantially os described, so that such out away or. depressed portion, while connected with and forlning part of the cup, shall lie within or line the nick in the scrcw-hea.d, as set foral.

2. A capped screw in'which the slot vor depression in the cap corresponding to the nick in thescrew-head is formed, substantially in the manner and for the purposes herein -shown and described. In testimony whereof, I have signed my name to this specification before two subscribing witnesses.

JOHN GARDNER.

Witnesses:

H. T. BLAKE, BLAKE. 

